Any active mechanical system uses an engine that converts chemical or electrical energy into mechanical work. In biological systems, such work is carried out by motor proteins. Despite the success of building rotary engines, designing and building artificial nanoscale counterparts of these complex biological motors has proven challenging.
Of the critical steps in creating nanoscale rotary engines is demonstrating their ability to convert local free energy into designed mechanical motion. Previous experiments led to multiple designs of rotary assemblies and established a certain level of directed motion.
Molecular dynamics simulations have also shown the feasibility of using a DNA helix to convert electric fields into torque. However, scientists find it difficult to achieve experimental demonstration of a rotary mechanism that is programmed for sustained conversion of electric potential into mechanical rotation.
According to Professor Aleksei Aksimentiev of the University of Illinois, typical macroscopic machines get inefficient at the nanoscale. Experts must develop new principles and physical mechanisms to realize electromotors at tiny scales.
A team of researchers led by Hendrik Dietz of the Technical University of Munich and Cees Dekker of the Delft University of Technology has recently produced the first working nanoscale electromotor in history. It was made possible by designing a turbine engineered from DNA powered by hydrodynamic flow inside a nanopore. Their study is discussed in the paper "A DNA turbine powered by a transmembrane potential across a nanopore."
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